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 #include &quot;mainwindow.h&quot;
 #include &quot;dialog.h&quot;

 #include &lt;QtGui&gt;
 #include &lt;QtSql&gt;
 #include &lt;QtXml&gt;

 extern int uniqueAlbumId;
 extern int uniqueArtistId;

 MainWindow::MainWindow(const QString &amp;artistTable, const QString &amp;albumTable,
                        QFile *albumDetails, QWidget *parent)
      : QMainWindow(parent)
 {
     file = albumDetails;
     readAlbumData();

     model = new QSqlRelationalTableModel(this);
     model-&gt;setTable(albumTable);
     model-&gt;setRelation(2, QSqlRelation(artistTable, &quot;id&quot;, &quot;artist&quot;));
     model-&gt;select();

     QGroupBox *artists = createArtistGroupBox();
     QGroupBox *albums = createAlbumGroupBox();
     QGroupBox *details = createDetailsGroupBox();

     artistView-&gt;setCurrentIndex(0);
     uniqueAlbumId = model-&gt;rowCount();
     uniqueArtistId = artistView-&gt;count();

     connect(model, SIGNAL(rowsInserted(QModelIndex, int, int)),
             this, SLOT(updateHeader(QModelIndex, int, int)));
     connect(model, SIGNAL(rowsRemoved(QModelIndex, int, int)),
             this, SLOT(updateHeader(QModelIndex, int, int)));

     QGridLayout *layout = new QGridLayout;
     layout-&gt;addWidget(artists, 0, 0);
     layout-&gt;addWidget(albums, 1, 0);
     layout-&gt;addWidget(details, 0, 1, 2, 1);
     layout-&gt;setColumnStretch(1, 1);
     layout-&gt;setColumnMinimumWidth(0, 500);

     QWidget *widget = new QWidget;
     widget-&gt;setLayout(layout);
     setCentralWidget(widget);
     createMenuBar();

     showImageLabel();
     resize(850, 400);
     setWindowTitle(tr(&quot;Music Archive&quot;));
 }

 void MainWindow::changeArtist(int row)
 {
     if (row &gt; 0) {
         QModelIndex index = model-&gt;relationModel(2)-&gt;index(row, 1);
         model-&gt;setFilter(&quot;artist = '&quot; + index.data().toString() + &quot;'&quot;) ;
         showArtistProfile(index);
     } else if (row == 0) {
         model-&gt;setFilter(&quot;&quot;);
         showImageLabel();
     } else {
         return;
     }
 }

 void MainWindow::showArtistProfile(QModelIndex index)
 {
     QSqlRecord record = model-&gt;relationModel(2)-&gt;record(index.row());

     QString name = record.value(&quot;artist&quot;).toString();
     QString count = record.value(&quot;albumcount&quot;).toString();
     profileLabel-&gt;setText(tr(&quot;Artist : %1 \n&quot; \
                              &quot;Number of Albums: %2&quot;).arg(name).arg(count));

     profileLabel-&gt;show();
     iconLabel-&gt;show();

     titleLabel-&gt;hide();
     trackList-&gt;hide();
     imageLabel-&gt;hide();
 }

 void MainWindow::showAlbumDetails(QModelIndex index)
 {
     QSqlRecord record = model-&gt;record(index.row());

     QString artist = record.value(&quot;artist&quot;).toString();
     QString title = record.value(&quot;title&quot;).toString();
     QString year = record.value(&quot;year&quot;).toString();
     QString albumId = record.value(&quot;albumid&quot;).toString();

     showArtistProfile(indexOfArtist(artist));
     titleLabel-&gt;setText(tr(&quot;Title: %1 (%2)&quot;).arg(title).arg(year));
     titleLabel-&gt;show();

     QDomNodeList albums = albumData.elementsByTagName(&quot;album&quot;);
     for (int i = 0; i &lt; albums.count(); i++) {
         QDomNode album = albums.item(i);
         if (album.toElement().attribute(&quot;id&quot;) == albumId) {
             getTrackList(album.toElement());
             break;
         }
     }
     if (!trackList-&gt;count() == 0)
         trackList-&gt;show();
 }

 void MainWindow::getTrackList(QDomNode album)
 {
     trackList-&gt;clear();

     QDomNodeList tracks = album.childNodes();
     QDomNode track;
     QString trackNumber;

     for (int j = 0; j &lt; tracks.count(); j++) {

         track = tracks.item(j);
         trackNumber = track.toElement().attribute(&quot;number&quot;);

         QListWidgetItem *item = new QListWidgetItem(trackList);
         item-&gt;setText(trackNumber + &quot;: &quot; + track.toElement().text());
     }
 }

 void MainWindow::addAlbum()
 {
     Dialog *dialog = new Dialog(model, albumData, file, this);
     int accepted = dialog-&gt;exec();

     if (accepted == 1) {
         int lastRow = model-&gt;rowCount() - 1;
         albumView-&gt;selectRow(lastRow);
         albumView-&gt;scrollToBottom();
         showAlbumDetails(model-&gt;index(lastRow, 0));
     }
 }

 void MainWindow::deleteAlbum()
 {
     QModelIndexList selection = albumView-&gt;selectionModel()-&gt;selectedRows(0);

     if (!selection.empty()) {
         QModelIndex idIndex = selection.at(0);
         int id = idIndex.data().toInt();
         QString title = idIndex.sibling(idIndex.row(), 1).data().toString();
         QString artist = idIndex.sibling(idIndex.row(), 2).data().toString();

         QMessageBox::StandardButton button;
         button = QMessageBox::question(this, tr(&quot;Delete Album&quot;),
                                        QString(tr(&quot;Are you sure you want to &quot; \
                                                   &quot;delete '%1' by '%2'?&quot;))
                                               .arg(title).arg(artist),
                                        QMessageBox::Yes | QMessageBox::No);

         if (button == QMessageBox::Yes) {
             removeAlbumFromFile(id);
             removeAlbumFromDatabase(idIndex);
             decreaseAlbumCount(indexOfArtist(artist));

             showImageLabel();
         }
     } else {
         QMessageBox::information(this, tr(&quot;Delete Album&quot;),
                                  tr(&quot;Select the album you want to delete.&quot;));
     }
 }

 void MainWindow::removeAlbumFromFile(int id)
 {

     QDomNodeList albums = albumData.elementsByTagName(&quot;album&quot;);

     for (int i = 0; i &lt; albums.count(); i++) {
         QDomNode node = albums.item(i);
         if (node.toElement().attribute(&quot;id&quot;).toInt() == id) {
             albumData.elementsByTagName(&quot;archive&quot;).item(0).removeChild(node);
             break;
         }
     }
<span class="comment"> /*
     The following code is commented out since the example uses an in
     memory database, i.e., altering the XML file will bring the data
     out of sync.

     if (!file-&gt;open(QIODevice::WriteOnly)) {
         return;
     } else {
         QTextStream stream(file);
         albumData.elementsByTagName(&quot;archive&quot;).item(0).save(stream, 4);
         file-&gt;close();
     }
 */</span>
 }

 void MainWindow::removeAlbumFromDatabase(QModelIndex index)
 {
     model-&gt;removeRow(index.row());
 }

 void MainWindow::decreaseAlbumCount(QModelIndex artistIndex)
 {
     int row = artistIndex.row();
     QModelIndex albumCountIndex = artistIndex.sibling(row, 2);
     int albumCount = albumCountIndex.data().toInt();

     QSqlTableModel *artists = model-&gt;relationModel(2);

     if (albumCount == 1) {
         artists-&gt;removeRow(row);
         showImageLabel();
     } else {
         artists-&gt;setData(albumCountIndex, QVariant(albumCount - 1));
     }
 }

 void MainWindow::readAlbumData()
 {
     if (!file-&gt;open(QIODevice::ReadOnly))
         return;

     if (!albumData.setContent(file)) {
         file-&gt;close();
         return;
     }
     file-&gt;close();
 }

 QGroupBox* MainWindow::createArtistGroupBox()
 {
     artistView = new QComboBox;
     artistView-&gt;setModel(model-&gt;relationModel(2));
     artistView-&gt;setModelColumn(1);

     connect(artistView, SIGNAL(currentIndexChanged(int)),
             this, SLOT(changeArtist(int)));

     QGroupBox *box = new QGroupBox(tr(&quot;Artist&quot;));

     QGridLayout *layout = new QGridLayout;
     layout-&gt;addWidget(artistView, 0, 0);
     box-&gt;setLayout(layout);

     return box;
 }

 QGroupBox* MainWindow::createAlbumGroupBox()
 {
     QGroupBox *box = new QGroupBox(tr(&quot;Album&quot;));

     albumView = new QTableView;
     albumView-&gt;setEditTriggers(QAbstractItemView::NoEditTriggers);
     albumView-&gt;setSortingEnabled(true);
     albumView-&gt;setSelectionBehavior(QAbstractItemView::SelectRows);
     albumView-&gt;setSelectionMode(QAbstractItemView::SingleSelection);
     albumView-&gt;setShowGrid(false);
     albumView-&gt;verticalHeader()-&gt;hide();
     albumView-&gt;setAlternatingRowColors(true);
     albumView-&gt;setModel(model);
     adjustHeader();

     QLocale locale = albumView-&gt;locale();
     locale.setNumberOptions(QLocale::OmitGroupSeparator);
     albumView-&gt;setLocale(locale);

     connect(albumView, SIGNAL(clicked(QModelIndex)),
             this, SLOT(showAlbumDetails(QModelIndex)));
     connect(albumView, SIGNAL(activated(QModelIndex)),
             this, SLOT(showAlbumDetails(QModelIndex)));

     QVBoxLayout *layout = new QVBoxLayout;
     layout-&gt;addWidget(albumView, 0, 0);
     box-&gt;setLayout(layout);

     return box;
 }

 QGroupBox* MainWindow::createDetailsGroupBox()
 {
     QGroupBox *box = new QGroupBox(tr(&quot;Details&quot;));

     profileLabel = new QLabel;
     profileLabel-&gt;setWordWrap(true);
     profileLabel-&gt;setAlignment(Qt::AlignBottom);

     titleLabel = new QLabel;
     titleLabel-&gt;setWordWrap(true);
     titleLabel-&gt;setAlignment(Qt::AlignBottom);

     iconLabel = new QLabel();
     iconLabel-&gt;setAlignment(Qt::AlignBottom | Qt::AlignRight);
     iconLabel-&gt;setPixmap(QPixmap(&quot;:/images/icon.png&quot;));

     imageLabel = new QLabel;
     imageLabel-&gt;setWordWrap(true);
     imageLabel-&gt;setAlignment(Qt::AlignCenter);
     imageLabel-&gt;setPixmap(QPixmap(&quot;:/images/image.png&quot;));

     trackList = new QListWidget;

     QGridLayout *layout = new QGridLayout;
     layout-&gt;addWidget(imageLabel, 0, 0, 3, 2);
     layout-&gt;addWidget(profileLabel, 0, 0);
     layout-&gt;addWidget(iconLabel, 0, 1);
     layout-&gt;addWidget(titleLabel, 1, 0, 1, 2);
     layout-&gt;addWidget(trackList, 2, 0, 1, 2);
     layout-&gt;setRowStretch(2, 1);
     box-&gt;setLayout(layout);

     return box;
 }

 void MainWindow::createMenuBar()
 {
     QAction *addAction = new QAction(tr(&quot;&amp;Add album...&quot;), this);
     QAction *deleteAction = new QAction(tr(&quot;&amp;Delete album...&quot;), this);
     QAction *quitAction = new QAction(tr(&quot;&amp;Quit&quot;), this);
     QAction *aboutAction = new QAction(tr(&quot;&amp;About&quot;), this);
     QAction *aboutQtAction = new QAction(tr(&quot;About &amp;Qt&quot;), this);

     addAction-&gt;setShortcut(tr(&quot;Ctrl+A&quot;));
     deleteAction-&gt;setShortcut(tr(&quot;Ctrl+D&quot;));
     quitAction-&gt;setShortcut(tr(&quot;Ctrl+Q&quot;));

     QMenu *fileMenu = menuBar()-&gt;addMenu(tr(&quot;&amp;File&quot;));
     fileMenu-&gt;addAction(addAction);
     fileMenu-&gt;addAction(deleteAction);
     fileMenu-&gt;addSeparator();
     fileMenu-&gt;addAction(quitAction);

     QMenu *helpMenu = menuBar()-&gt;addMenu(tr(&quot;&amp;Help&quot;));
     helpMenu-&gt;addAction(aboutAction);
     helpMenu-&gt;addAction(aboutQtAction);

     connect(addAction, SIGNAL(triggered(bool)), this, SLOT(addAlbum()));
     connect(deleteAction, SIGNAL(triggered(bool)), this, SLOT(deleteAlbum()));
     connect(quitAction, SIGNAL(triggered(bool)), this, SLOT(close()));
     connect(aboutAction, SIGNAL(triggered(bool)), this, SLOT(about()));
     connect(aboutQtAction, SIGNAL(triggered(bool)), qApp, SLOT(aboutQt()));
 }

 void MainWindow::showImageLabel()
 {
     profileLabel-&gt;hide();
     titleLabel-&gt;hide();
     iconLabel-&gt;hide();
     trackList-&gt;hide();

     imageLabel-&gt;show();
 }

 QModelIndex MainWindow::indexOfArtist(const QString &amp;artist)
 {
     QSqlTableModel *artistModel = model-&gt;relationModel(2);

     for (int i = 0; i &lt; artistModel-&gt;rowCount(); i++) {
         QSqlRecord record =  artistModel-&gt;record(i);
         if (record.value(&quot;artist&quot;) == artist)
             return artistModel-&gt;index(i, 1);
     }
     return QModelIndex();
 }

 void MainWindow::updateHeader(QModelIndex, int, int)
 {
     adjustHeader();
 }

 void MainWindow::adjustHeader()
 {
     albumView-&gt;hideColumn(0);
     albumView-&gt;horizontalHeader()-&gt;setResizeMode(1, QHeaderView::Stretch);
     albumView-&gt;resizeColumnToContents(2);
     albumView-&gt;resizeColumnToContents(3);
 }

 void MainWindow::about()
 {
     QMessageBox::about(this, tr(&quot;About Music Archive&quot;),
             tr(&quot;&lt;p&gt;The &lt;b&gt;Music Archive&lt;/b&gt; example shows how to present &quot;
                &quot;data from different data sources in the same application. &quot;
                &quot;The album titles, and the corresponding artists and release dates, &quot;
                &quot;are kept in a database, while each album's tracks are stored &quot;
                &quot;in an XML file. &lt;/p&gt;&lt;p&gt;The example also shows how to add as &quot;
                &quot;well as remove data from both the database and the &quot;
                &quot;associated XML file using the API provided by the QtSql and &quot;
                &quot;QtXml modules, respectively.&lt;/p&gt;&quot;));
 }</pre>
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